Compound boiler



(No Model.) 3 Sheeia s-Sheet 1.

' J. J. HOGAN.

' COMPOUND BOILER.

No. 425,945; Patented Apr. 15 1890.

(No Model.) 3 Sheets-Sheet 2. J. J. HOGAN.

COMPOUND BOILER. No. 425,945. Patented Apr. 15, 1890.

(No Model.) V 3 Sheets-Sheet 3.

J. J. HOGAN.

COMPOUND BOILER. No. 425,945. 7 Patented Apr. 15, 1890.

UNITED STATES PATENT QFFICE.

JOHN J. HOGAN, or BROOKLYN, NEW YORK, ASSIGNOR TO THE HOGAN ENGINEERINGCOMPANY, OF NEW YORK.

COMPOUND BOILER.

SPECIFICATION forming part of Letters Patent No. 425,945, dated April15, 1890.

Application filed January 21, 1890. Serial No. 337,587. (No model.)

To all whom it may concern Be it known that 1, JOHN J. HOGAN, a citizenof the United States, residing at Brooklyn, Kings county, New York, haveinvented certain new and useful improvements in Oompound Boilers, fullydescribed and represented in the following specification and theaccompanying drawings, forming a part of the same.

This invention relates especially to that class of boilers which arefilled entirely with water and the water circulated therefrom throughone or more heating-radiators for the purpose of warming apartments. Insuch boilers the heated fluid is discharged from the top of the boilerand the colder returnfluid from the radiators is commonly con ducted tothe bottom of the boiler, from which it ascends to the top as it becomesheated. So long as the radiators are in use the circulation of theboiler is easily maintained and the metallic surfaces adjacent to theheated gases are prevented from overheating; but when such radiators arecut off from the boiler while a fire is in the furnace the hottestsurfaces are liable to generate steam, and thus displace the water fromcontact with the metal, which thus becomes overheated.

The object of the present invention is to furnish a construction inwhich the heated gases mayoperate most efficiently upon the water andthe circulation within the boiler be facilitated when the radiators arecut off.

The annexed. drawings show three modifications of my invention, Figure 1being a plan of the boiler; Fig. 2, a vertical section, where hatched,through the center line of the same. Flg. 3 is a vertical section, Wherehatched, of an alternative construction; and Fig. 4, a plan 1n sectionon line so a: in Fig. 3. Fig. 5 is a vertical section, where hatched, ofanother modification; and Fig. 6, a section of the same on line y y inFig. 5.

a is a fire-box formed within an annular water-leg I), having anaperture 1) formed in one side for a fuel-door.

o is a hollow crown-plate, shown in the d rawings as formed in one pieceby casting with the water-leg and perforated with vertical smoke tubesor passages d.

t is a casing extended upward from the outer edge of the crown-plate andprovided with a smoke-outlet 25 near its top.

4 is a reservoir, which is shown fixed in the top of the casing atsuitable distance above the crown-plate c to form a combustion-chamher.9, and of such dimensions as to form an annular space r between thereservoir and casing for the circulation of the heated gases which risethrough the smoke-tubes d.

The upper part of the reservoir-section in all the modifications isshown connected with the upper part of the fire-box section bywatertubes adapted to conduct the heated fluid from the top of thefire-box section to the top of the reservoir, and the lower parts of thetwo sections are in like manner connected by watertubes adapted toconduct the fluid from the lower part of the reservoir to the lower partof the water-box section or fire-leg 1). Such connections furnish acomplete avenue for internal circulation when the radiators are cut offfrom the boiler, the water circulating, as indicated by the arrows inFigs. 2, 3, and 5, downward from the bottom of the reservoir-section andupward from the top of the fire-box section.- V

The crown-plate of the fire-box section is preferably domed, as shown inFigs. 2 and 5, and as the heat is greatest in the center portion of suchplate the most effective means of discharging the heated fluid upwardlyfrom such plate is by the central tube 6, Figs. 3 and 5, which isconnected with the bottom of the reservoir-section, and is shownextended upward within the same nearly to the top.

In the preferred construction shown in Fig; 2 the water-connectionbetween the bottom of the reservoir and the bottom of the fire-boxsection consists in vertical pipes f, extended outside the casing andhaving branches at the top and bottom which penetrate, respectively,into the top of the reservoir and the bottom of the water-leg. The

branches which penetrate the water-leg are shown united to the pipes fby Ts g, and branches 9 are shown extending outwardly from the same toreceive the return-fluid from the radiators. With the construction shownin Fig. 2 the return-fluid, when the radiators are in operation, entersby the branches 9', circulates freely within the waterleg, and passesupward into the hollow crownplate 0. The products of combustion, passingthrough the smoke-tubes (i into the space 8, heat the water in thecrown-plate to a high degree, and the fluid, passing upward through thecentral tube 6, is discharged directly into the hot-water outlet 71inserted in thetop of the reservoir. While the radiators are in use thedraft upon such outlet may also draw such water from the reservoir as isheated by the contact of the gases in the space 1'', such fluid beingreplaced by an upward flow through the pipes f, which are supplied, likethe water-leg, from the inlets g. When the radiators are cut off whilethe fire is. in operation, the heated fluid continues to pass upwardthrough the central pipe 6, and passes downward, as indicated by thearrows in the figure, through the outer parts of the reservoir andthrough the pipes f to the bottom of the water-leg. The Water-leg,although exposed to the greatest heat of the fire, is thus supplied witha continuous fiow of fluid, and no injury to the metal can result.

The construction in Fig. 5 is the same as that in Fig. 2, except thatthe water connection between the bottom of the reservoir and the bottomof the fire-box is formed by extending tubes f throughthe top of thecrownplate downward inside the water-leg nearly to its bottom andapplying aguard f in the chamber 3 to protect the pipes from the heat.The tubes of this construction do not pass outside of the casing, andthe water-leg is preferably formed, as shown in Fig. 6, with a verticalenlargement e, adapted to admit the pipe f. The water-leg is suppliedwith an inlet g near its bottom to receive the returnfluid near theradiators. The operation with this construction is the same as alreadydescribed, the pipes f furnishing an avenue for downward circulationwhen the boiler is cut off from the radiators and furnishing with thecentral pipe 6 an avenue for internal circulation when the'radiators arein use and the return-fluid enters at the inlet 9 The construction shownin Figs. 2 and 5 is similar in possessing a central. water-connectionbetween the upper part of the firebox and reservoir-sections; but Fig. 3shows the connection between the upper parts of the sections formed byvertical pipes k, which are extended outside of the casing and terminatein branches which penetrate the two sections. These pipes may beconducted inside the casing. The lower parts of the sections areconnected, as in Fig. 2, by vertical pipes f, and the fire-box sectionis shown provided with an inlet 9 to receive the returnfluid from theradiators, althoughthe lower ends of the pipes f may, if preferred, beprovided with branches for such purpose. In this latter construction thetop of the crownplate is made flat to facilitate the movement of thefluid toward the periphery of the crownplate in its upward movement tothe pipes 76 and top of the reservoir 1'.

The fuel-door b is indicated in Figs. 2 and",

5 as formed at the rear side of the boiler; but in Fig. 4 the door isindicated in dotted lines at the side of the boiler opposite the pipeg", with one of the pipes at its right-hand side and one of the pipes fat its left-hand side.

I am aware that it is not new to furnish a fire-pot with awater-boilerof some kind and connect the same with a reservoir placed in thesmoke-flue of such boiler, and that such reservoir has been connectedwith such boiler by a single pipe adapted only for an upward movement ofthe fluid. In such arrangement the gases passing from the smoke-fluegive up a portion of their heat to the water-reservoir; but my inventiondiifers widely from such construction, in having the top and bottom ofthe reservoir connected, respectively, with the top and bottom of thefire-box section, by which construction a perfect circulation within theboiler system may be preserved at all times whether or not any coldfluid is passing from the radiators into the fire-box section.

- The precise construction of the fire-box section is wholly immaterialto my invention, provided its upper and lower parts are conn eeted,respectively, with the upper and lower parts of the reservoir, and it isalso immaterial whether the reservoir be placed immediately over thefire-box section, provided it is located in the smoke-flue, so as to beheated by the gases which escape from the fire-box. It is thereforeimmaterial whether the pipes [6,f, or f be vertical, as shown herein, asthe essential feature of the invention is the connection of the tops andbottoms of the two sections by independent water-connections adapted forthe downward and upward circulation of the fluid within the boiler whenthe external circulation is cut off.

The fire-box construction shown herein is especially advantageous, as itis readily adapted for construction in cast-iron, and the reservoir inlike manner, by the use of a detachable cover, as shown in the drawings,is also readily adapted for forming of cast-iron, and connection to thefire-section, in the manner described.

Acrown-plate formedwithnumerous smokepas'sages and a water-leg dependingfrom its margin presents a very large amount of surface to the hottestpart of the fire, and thus develops a great degree of economy in the useof fuel, while the superposition of the reservoir immediately over theperforated crownplate exposes the surface of the reservoir in the mosteffective manner to the gases which are passing to the chimney, whilethe provision of the combustion-chamber between the reservoir and thecrown-plate promotes the combustion of the gases in the most effectivemanner before their escape to the chimney;

The objects of my invention are especially promoted by exposing theconnection between the top of the fire-box sect-ion to the top of thereservoir-section to a greater heat than the connection between thelowerpart of such sections, as the water heated in the fire-box sectionis thus conducted to the upper part of. the reservoir-section, whichwould naturally contain the hottest fluid. Such objects would be bestpromoted by placing the pipes 70 inside the casing t and permitting theheated gases to operate upon them, while for the same reasons it isdesirable to protect the pipes f which are located Within the casing,from the heated gases, to promote a downward circulation within thesame.

The construction claimed herein is shown in pending application, SerialNo. 337,588, filed January 21,1890, but not claimed therein, the claimsin said application, Serial No. 337,588, being limited to a specialconstruction not shown in the present application, Serial No. 837,587.

Having thus set forth the nature of the invention, what is claimedherein is 1. A compound boiler consisting in a firebox section and areservoir-section, a watereonnection between the upper parts of suchsections, a water-outlet from the reservoirsection, and a water-inlet tothe fire-box section, the whole arranged and operated substantially asherein set forth.

2. A compound boiler consisting in a firebox section and areservoir-section, a pipe connecting the centers of the two sections, a

water-connection between the lower parts of the two sections, awater-outlet from the res-v ervoir, and a water-inlet to the fire-boxsection, the whole arranged and operated substantially as herein'setforth.

3. A compound boiler consisting in a firebox section and areservoir-section, a pipe connectin the centers of the two sections andextended upward within the reservoir-section nearly to its top, awater-connection between the lower parts of the two sections, awateroutlet from the top of the reservoir, and a Water-inlet tothefire-box section, the whole arranged and operated substantially asherein set forth.

4:. A compound boiler consisting in a firebox section having an annularwater-leg and hollow perforated crown-plate, a reservoirsectionconnected at its bottom withthe center of the crown-plate by a tubeextended nearly to the top of the reservoir-section, a casing extendedfrom the crown-plate to the top of the reservoir and having asmoke-outlet near its top, water-tubes connecting the bottom of thereservoir-section and the bottom of the water-leg outside of the casing,a water-outlet from the top of the reservoir-section, and a water-inletat the bottom of the water-leg, the whole arranged and operatedsubstantially as herein set forth.

In testimony whereof I have hereunto set my handin the presence of twosubscribing witnesses.

JOHN J. HOGAN.

Witnesses:

ANSON O. KITTREDGE, THos. S. CRANE.

